Downloading TesselManiac! 0.9b for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. This Mac application is an intellectual property of Kevin Lee. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. The software lies within Design & Photo Tools, more precisely 3D Modeling.
From the developer:
TesselManiac! is a free-to-use program for creating Escher-like tessellations. A subset of the The Flipping Tile Game is included, which is a new way to learn about the four isometries of the plane; translation, rotation, reflection, and glide-reflection.
You may want to check out more Mac applications, such as TkMatMan, 3D Invigorator PS or Microspot Interiors Pro, which might be similar to TesselManiac!.